1. Field of the Invention
This invention generally relates to a bicycle hub. More specifically, the present invention relates to a bicycle disc brake hub for mounting a disc brake rotor thereto.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One component that has been extensively redesigned is the bicycle brake systems.
Recently, bicycles have been equipped with disc brake systems, which are known examples of bicycle brake devices. A disc brake system usually has a caliper connected to a brake lever mounted on the bicycle frame, and a disc brake rotor. The disc brake rotor is fixedly connected to a bicycle disc brake hub provided in the middle of a wheel of the bicycle. A bicycle disc brake hub generally has a hub axle, a hub shell rotatably mounted on the hub axle and a rotor attachment portion fixed to the hub shell. The hub axle is non-rotatably mounted to the bicycle frame. The hub shell is mounted around an external periphery of the hub axle such that it is capable of rotating around the hub axle. The rotor attachment portion configured to attach the disc brake rotor thereto. The hub shell has a cylinder portion provided between a pair of spoke mounting flanges. The rotor attachment portion is provided at one end of the hub shell, and has a greater outside diameter than the cylinder of the hub shell (see, for example, Japanese Laid-Open Patent Application No. 2004-142739 and Japanese Laid-Open Patent Application No. 2004-224337).
Increasing the diameter of the hub axle is an effective measure for improving the rigidity in this type of bicycle disc brake hub. However, if the hub axle is increased in diameter, the outside diameter of the hub shell must also increase accordingly. In this case, with this type of disc brake hub, the outside diameter of the rotor attachment portion increases together with the increase in the diameter of the hub shell. Thus, there must also be an increase in the inside diameter of the rotor attached to the rotor attachment portion.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved bicycle disc brake hub. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.